The RNAi Machinery in the Fungus Is Not Very Active in Synthetic Medium and Is Related to Transposable Elements.

Small RNAS (sRNAs) participate in regulatory RNA interference (RNAi) mechanisms in a wide range of eukaryotic organisms, including fungi. The fungus , a model for the study of secondary metabolism, contains a complete set of genes for RNAi pathways. We have analyzed by high-throughput sequencing the content of sRNAs in total RNA samples of grown in synthetic medium in the dark or after 1 h of illumination, using libraries below 150 nt, covering sRNAs and their precursors.

Photoreceptors.

Light is an important modulating signal in fungi. species stand out as research models for their phytopathogenic activity and their complex secondary metabolism. This includes the synthesis of carotenoids, whose induction by light is their best known photoregulated process.

The lncRNA Is a -Related Regulatory Element with Broad Effects on the Transcriptome.

Carotenoid biosynthesis in the fungus is regulated by environmental factors, with light being the main stimulating signal. The CarS RING-finger protein plays an important role in the downregulation of structural genes of the carotenoid pathway. A recent transcriptomic analysis on the effect of mutation identified a gene for a long non-coding RNA (lncRNA) upstream of , called , the deletion of which results in increased mRNA levels and lack of carotenoid production.

Impact of the White Collar Photoreceptor WcoA on the Transcriptome.

The proteins of the White Collar 1 family (WC) constitute a major class of flavin photoreceptors, widely distributed in fungi, that work in cooperation with a WC 2 protein forming a regulatory complex. The WC complex was investigated in great detail in , a model fungus in photobiology studies, where it controls all its major photoresponses. The fungus , a model system in the production of secondary metabolites, contains a single WC-1 gene called .

A novel lncRNA as a positive regulator of carotenoid biosynthesis in Fusarium.

The fungi Fusarium oxysporum and Fusarium fujikuroi produce carotenoids, lipophilic terpenoid pigments of biotechnological interest, with xanthophyll neurosporaxanthin as the main end product. Their carotenoid biosynthesis is activated by light and negatively regulated by the RING-finger protein CarS. Global transcriptomic analysis identified in both species a putative 1-kb lncRNA that we call carP, referred to as Fo-carP and Ff-carP in each species, upstream to the gene carS and transcribed from the same DNA strand.

Modulation of Activity of a Carotenoid Pathway Through the Use of the TeT-on Regulatory System: Application in the Fungus Fusarium fujikuroi.

Carotenoids are widespread pigments in photosynthetic species, but they are also found in nonphotosynthetic microorganisms, such as bacteria and fungi. The amenability of fungi to genetic studies have made some fungal species advantageous models in the study of the genetics and biochemistry of carotenoid biosynthesis, while others have been used for biotechnological carotenoid production. The availability of molecular techniques that allow modulating the expression of target genes is a powerful tool in the manipulation of carotenoid synthesis.

Comparative transcriptomic analysis unveils interactions between the regulatory CarS protein and light response in Fusarium.

Background: The orange pigmentation of the agar cultures of many Fusarium species is due to the production of carotenoids, terpenoid pigments whose synthesis is stimulated by light. The genes of the carotenoid pathway and their regulation have been investigated in detail in Fusarium fujikuroi. In this and other Fusarium species, such as F.

Carotenoid Biosynthesis in Fusarium.

Many fungi of the genus stand out for the complexity of their secondary metabolism. Individual species may differ in their metabolic capacities, but they usually share the ability to synthesize carotenoids, a family of hydrophobic terpenoid pigments widely distributed in nature. Early studies on carotenoid biosynthesis in have been recently extended in and , well-known biotechnological and phytopathogenic models, respectively.

Transcriptional basis of enhanced photoinduction of carotenoid biosynthesis at low temperature in the fungus Neurospora crassa.

Stimulation by light of carotenoid biosynthesis in the mycelia of the fungus Neurospora crassa starts with transient transcriptional induction of the structural genes of the pathway triggered by the White Collar photoreceptor complex. Most studies on this process were carried out under standard growth conditions, but photoinduced carotenoid accumulation is more efficient if the fungus is incubated at low temperatures, from 6 to 12 °C. We have investigated the transcriptional photoresponse at 8 °C of the genes for proteins that participate in the carotenoid pathway.